The present invention relates to a document registration apparatus for use in a document processing system, and more particularly, to a document registration apparatus having an improved document drive system for use in a document inserting station or a document queuing station.
Various document processing systems require that a particular edge of a processed document is aligned relative to a particular direction in the system. For example, enclosures which are to be inserted into an envelope should be aligned relative to the envelope prior to insertion in order to avoid processing difficulties. Furthermore, some documents which are to be transported away from a particular queuing station, to another adjacent document raceway, should be aligned at the queuing station relative to the raceway, in order to facilitate the processing of the documents.
Devices which register a particular edge of a document to a particular direction are known. For example, U.S. Pat. Nos. 5,255,906 which issued to Ballard, et al. on Oct. 26, 1993 and U.S. Pat. No. 5,263,705 which issued to Schmaling on Nov. 23, 1993, each of which are hereby incorporated by reference, disclose a very effective document registration device which is simple in design, is not difficult to adjust for proper alignment, and provides easy access to jammed documents for removal thereof. The apparatus disclosed in the aforementioned patents have been effectively utilized by the assignee of the instant application in its Mail Center 2000.TM. Spectrum.TM. Inserting System to register numerous types of documents for various processing purposes. However, the Applicants of the instant invention have identified certain potential drawbacks (as discussed in more detail below) which may occur in the prior art structure and have invented the structure set forth in the instant application to assuredly prevent such drawbacks from occurring. Referring to FIGS. 1-4, which show the prior art structure of the aforementioned patents, a brief explanation of the prior art structure is set forth below together with a discussion of the potential drawbacks mentioned to above.
Document registration apparatus 10 of the present invention is used in conjunction with a document conveyor system 11 which transports a document 12 along a path 13 from an upstream position to a downstream position in the direction of arrow D. Positioned between the upstream position and the downstream position is a document registration position 16 where a document 12 having a flap 12a is stopped in its path and is held or queued until the processing system of which conveyor system 11 is a part is ready to process document 12. At the same time, document registration apparatus 10 aligns document 12 relative to path 13, or, if desired, some other document raceway in the system. Although FIG. 3 shows a single document 12, it is to be understood that the present invention is applicable to situations where document 12 is a stack of documents. Document registration apparatus 10 includes a holder unit 19 and a document registration unit 20 which includes four registration stops 21, 22, 23 and 24 on the downstream end thereof and two non-driven urge rollers 25 and 26 on urge roller arms 25A-B and 26A-B, respectively, on the upstream end of unit 20. Holder 19 is attached, for example, to a document inserting station or a document queuing station (neither of which is shown) of a document processing system. Non drive urge rollers 25 and 26 are spaced at lateral positions between the lateral positions of registration stops 21 and 22 on the one hand, and the lateral positions of registration stops 23 and 24 on the other hand, respectively (see FIG. 2). Unit 20 pivots within holder 19 around pivot axis 31. A rotary solenoid 27 is linked to a pivoting arm 14 by a pin 28 which rides in a slot 15 of pivoting arm 14. Pin 28 moves along a circular path on each actuation of solenoid 27 and reciprocates in slot 15, thereby rocking pivot arm 14. As pivot arm 14 rocks, document registration unit 20 pivots around pivot axis 31.
Registration stops 21-24 are used to stop and align document 12 at document registration position 16, and then to release it for further processing. Document 12 is stopped and aligned at this position so that it can subsequently be processed with minimal skew relative to path 13, or if desired, some other document raceway as discussed above. For example, if document 12 is an envelope into which enclosures will be inserted, then registration stops 21-24 ensure that the envelope will be aligned relative to insertion of the enclosures. This insertion process can take place at document registration position 16 (where the envelope will be held open by an envelope opening claw) or, if desired, at a subsequent location along path 13. Similarly, if document 12 is an enclosure which will be subsequently inserted into an envelope, then registration stops 21-24 will ensure that the enclosure will be aligned relative to the envelope.
In order to stop document 12 at document registration position 16, document registration unit 20 is normally urged clockwise to position A (FIG. 3) when solenoid 27 is not energized. In position A, registration stops 21-24 extend into document path 13 and preferably project below the plane of conveyor system 11, so as to block document 12 from being transported further downstream by conveyor system 11. In the preferred embodiment, conveyor system 11 includes two conveyor belts 11A and 11B (see FIG. 4) which move in synchronization. Laterally spaced on each side of conveyor belts 11A and 11B are registration stops 21, 22 and 23, 24 respectively. The projection of stops 21-24 below the plane of conveyor system 11 assures that document 12 cannot slip past stops 21-24. Registration stops 21-24 are laterally-spaced along document registration unit 20 so that when document 12 is stopped at document registration position 16, the downstream edge 12b (see FIGS. 3 and 4) of document 12 is aligned with respect to document path 13, or if desired, any other path with which it is designed to align document 12. The continued travel of conveyor system 11 while document 12 is stopped assures that document 12 registers completely against stops 21-24. When it is time to release document 12, solenoid 27 is energized to pivot unit 20 to position B (see FIG. 3) where non drive urge rollers 25 and 26 urge document 12 against conveyor system 11, thus increasing the frictional force between document 12 and conveyor system 11. The increased frictional force is supposed to stop any slippage between document 12 and conveyor system 11 and moves document 12 downstream for further processing since registration stops 21-24 have pivoted out of the path of document 12.
As document 12 moves in the downstream direction, it encounters exit pinch rollers 32 and 33 which are mounted on independent sets of support arms 34A-34B, 35A-35B, corresponding to exit pinch rollers 32 and 33, respectively and which pivot about pivoting axis 31. Arms 34A, 34B, 35A, 35B and rollers 32 and 33 are respectively spring biased by separate compression springs (not shown) such that rollers 32 and 33 are urged against conveyor system 11. When a document 12 is released by moving registration stops 21-24 to position B, the released document 12 is caught in the nip between conveyor belts 11A and 11B and their respective pinch rollers 32, 33 so that the released document 12 is urged against conveyor system 11 by rollers 32, 33 and driven out of document registration apparatus 10. Moreover, when registration stops 21-24 are moved back to position A, the next document 12 is held in place. The mounting of rollers 32 and 33 on separate support arms 34A-34B, and 35A-35B results in minimal "shingling" of documents when a stack of documents exit the document registration apparatus 10. This is because rollers 32 and 33 and arms 34A-34B and 35A-35B can move away from conveyor system 11 as required by the thickness of document 12 to allow document 12 to pass without lifting the remainder of unit 20.
While the above-discussed design is very effective for many processing applications, it was discovered by the Applicants that when the document registration apparatus 10 was used at an inserting station, a number of potential problems existed. That is, document registration apparatus 10 can be used to receive and register envelopes for subsequent insertion of materials into those envelopes. In operation, an envelope 12 leaves a conventional flapper station where the envelope flap 12A is opened and the entire envelope 12 is transported by conveyor system 11 from the flapper station into the document registration apparatus 10 to await receipt of envelope 12 with registration stops 21-24 in the down position A. When the conveyor system 11 has driven envelope 12 up to stops 21-24, a conventional detector detects the correct positioning of envelope 12 and triggers a conventional envelope claw mechanism to operate to open the throat of the envelope to permit insertion of inserts into envelope 12. In the above-described structure the registration stops 21-24 and the non-driven urge rollers 25-26 are each mounted on a single structure 20B which pivots above axis 31. Thus, when the stops 21-24 are in the position A of FIG. 3, the non-driven urge rollers 25 and 26 are disposed away from the conveyor 11 and the envelope 12. Accordingly, the envelope 12 is only driven to the stops 21-24 by the forces developed from the weight of the envelope pressing against conveyor 11. However, slippage occurs between the conveyor belts 11A, 11B and the bottom of envelope 12 such that the conveyor belts 11A, 11B fail to deliver the envelope 12 to the stops 21-24. When this occurs, the system is set up, after a predetermined period of time has elapsed, to attempt to eject any envelopes in the document registration apparatus 10 or simply to indicate that a jam has occurred. Moreover, if slippage occurs between envelope 12 and one of the belts 11A and 11B, it is possible that the detector would still identify the envelope as being properly registered against the stops when in fact the envelope was delivered to stops 21-24 in a skewed position. If this situation occurred, the envelope claws would be activated but would be unable to properly open the throat of the envelope such that when the inserts were presented for insertion a jam could occur.
Previous attempts to correct the above-discussed problems included adding additional urge springs at the flapper station. The urge springs placed a biasing force on flap 12A of the envelope as it was carried away from the flapper station by the conveyor means 11. It was believed that the added force would help drive the envelope 12 completely to the registration stops 21-24. However, this solution proved unsatisfactory because the urge springs force, depending on the length of the flaps, tended to overdrive the flap 12a resulting in a partial closure of the flap 12a which would interfere with the subsequent inserting process and cause a jam in the document registration apparatus 10.
In addition to the above problem, it was also observed in the prior art structure that even if the envelope 12 was properly registered against the registration stops 21-24 such that the inserts were effectively inserted into envelope 12, the stuffed envelope 12 was not always effectively driven out of the document registration apparatus 10 subsequent to the moving of the registration stops 21-24 from the position A to position B. That is, if the frictional retarding forces acting on the stuffed envelopes was too great, the conveyor 11 together with the force exerted by the rollers 25, 26 would not always be capable of driving the envelope 12 out of the document registration apparatus 10. If this situation occurred, when the next envelope 12 was presented to receive its inserts, a jam would occur.